不同射野入射角度对食管癌放射治疗剂量学的影响  

Effect of different incidence angles on dosimetric parameters of radiotherapy for esophageal cancer

作　　者：吕明月[1] 李萍[1] 陈韦翔 王奕鸣[1] LV Mingyue;LI Ping;CHENWeixiang;WANG Yiming(Department of Oncology,the First Affiliated Hospital of Ji'nan University,Guangzhou 510630,China)

机构地区：[1]暨南大学附属第一医院肿瘤科

出　　处：《中国医学物理学杂志》2019年第8期908-913,共6页Chinese Journal of Medical Physics

摘　　要：目的:比较不同入射角度的食管癌放射治疗计划间的剂量学差异,从而选取一种既能最优化靶区剂量又能使危及器官损伤最小的计划。方法:选择11例食管癌患者,为每例患者制定4套放疗计划,包括三维适形放射治疗(3D-CRT)、4野调强放射治疗(4F-IMRT)、7野调强放射治疗(7F-IMRT)和9野调强放射治疗(9F-IMRT)。PTVg和计划靶区(PTV)的处方剂量分别为60 Gy/27 F和50 Gy/27 F。比较不同计划中的靶区和危及器官的剂量学参数。结果:4F-IMRT计划中PTVg的CI和PTV的HI、CI优于3D-CRT计划,4F-IMRT计划中PTV的CI优于7F-IMRT,差异具有统计学意义(P<0.05)。肺的受照剂量中,4F-IMRT计划中V20低于3D-CRT计划,V20、V30低于7F-IMRT计划,V5低于9F-IMRT计划,差异具有统计学意义(P<0.05)。4组计划中的脊髓Dmax<45 Gy,心脏V33<46%,均达到计划要求。结论:4F-IMRT计划与7F-IMRT、9F-IMRT计划相比,心脏、脊髓剂量差异不显著,但是肺的受量明显降低且患者接受照射的时间较7F-IMRT、9F-IMRT计划减少2~3倍。4F-IMRT计划能提高靶区适形度,更好地保护危及器官,显著减少肺低剂量区体积。Objective To compare the dosimetric differences among esophageal cancer plans with different incidence angles for determining an optimal plan which can optimize target doses and minimize the damages to organs-at-risk.Methods Eleven patients with esophageal cancer were enrolled in this study.Four radiotherapy plans,namely three-dimensional conformal radiotherapy(3D-CRT),4-field intensity-modulated radiotherapy(4F-IMRT),7-field intensity-modulated radiotherapy(7F-IMRT)and 9-field intensity-modulated radiotherapy(9F-IMRT),were designed for each patient.The prescription dose of PTVg and planning target volume(PTV)was 60 Gy/27 F and 50 Gy/27 F,respectively.The dosimetric parameters of target areas and organs-at-risk in different plans were compared.Results 4F-IMRT plan was superior to 3D-CRT plan in the conformity index(CI)of PTVg and the CI and homogeneity index(HI)of PTV,and was superior to 7F-IMRT plan in the CI of PTV,with statistical differences(P<0.05).The V20 of lung in 4F-IMRT plan was lower than that in 3D-CRT plan;the V20 and V30 of lung in 4F-IMRT plan were lower than those in 7F-IMRT plan;and the V5 of lung in 4F-IMRT plan was lower than that in 9F-IMRT plan,with significant differences(P<0.05).In the 4 kinds of plans,the maximum dose of spinal cord was less than 45 Gy and the V33 of the heart was less than 46%,which met the clinical requirements(P>0.05).Conclusion The doses of the heart and spinal cord in 4F-IMRT plan are similar to those in 7F-IMRT and 9F-IMRT plans,but the lung dose of 4F-IMRT plan is significantly reduced and the radiation time was 2-3 times less than that of 7F-IMRT and 9F-IMRT plans.4F-IMRT plan can not only improve target conformity,but also better protect organs-at-risk and significantly reduce the low-dose volume of lung.

关 键 词：食管癌 三维适形放射治疗 调强放射治疗 剂量学比较 

分 类 号：R812[医药卫生—放射医学] R735.1[医药卫生—临床医学]